I'm a pretty big fan of the app Cerberus, you don't need root for it to work but there's more functionality if you're rooted. Wifi Tether for Root Users is another cool app, you can't get it on the market but you can Google search to download the apk. Root Tools and Boot Logo Changer are both by JRummy (the guy who made Android Overclock) and they're both great apps for more customization